目的: 研究L-精氨酸（L-Arg）对大鼠血管损伤后内膜增生及相关细胞周期调控基因表达的影响。 方法:大鼠分为假手术组，球囊损伤组（又分为术后48 h 、7 d和14 d亚组）及球囊损伤+L-Arg组。取各组实验动脉段测新生内膜面积，并采用免疫组化及计算机图像分析法测细胞周期依赖性激酶2（CDK2）、细胞周期蛋白E(cyclin E) 和增殖细胞核抗原(PCNA) 的表达水平。结果: 球囊损伤后14 d组的血浆NO水平低于假手术组(P＜0.01)，CDK2、cyclin E及PCNA均于球囊损伤术后48 h在中膜表达，第7 d、14 d在内膜表达，中膜几无表达，随着内膜增厚表达水平上升。与球囊损伤后14 d组相比，球囊损伤+L-Arg组的血浆NO水平增高（P＜0.01），新生内膜面积少59.1%(P＜0.01) ，CDK2、cyclin E及PCNA的阳性表达指数分别低36.1%，46.3%和76.2%（P均＜0.01）。结论: L-Arg可有效抑制血管损伤后内膜增生, 其机制可能与逆转CDK2、cyclin E及PCNA的过表达从而抑制血管平滑肌细胞增殖有关。%AIM: To investigate the effect of L-arginine (L-Arg) on intimal proliferation and expression of related cell cycle regulatory factors after vascular injury in rats. METHODS: Rats were divided into three groups :sham operation group, balloon injury group(this group included balloon 48 h,7 d and 14 d subgroup) and balloon+L-Arg group. Neointima area were calculated morphologiocally. The expression of cyclin dependent kinase-2(CDK2),cyclin E and proliferation cell nuclear antigen (PCNA) were measured by means of immunohistochemical technique and computer image analyzer. RESULTS: After vascular balloon injury, the level of plasma NO decreased, CDK2、cyclin E and PCNA expressed in the media at 48 h and in the neointima at 7 d and 14 d but with low and undetected expression in the media, the expression of CDK2, cyclin E and PCNA increased with the intima thickening. Compared with balloon 14 d group, the plasma NO level increased (P＜0.01）, the neointima area reduced by 59.1%(P＜0.01) and the positive expression indexes of CDK2, cyclin E and PCNA decreased by 36.1%, 46.3% and 76.2% respectively in balloon+L-Arg group (P all＜0.01）. CONCLUSION: L-Arg can effectively repress intima proliferation after vascular injury, which may be associated with its inhibiting the proliferation of vascular smooth muscle cell through downregulating the excessive expression of CDK2, cyclin E and PCNA.
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